The invention discloses a preparation method and applications of a foam nickel-loaded iron-nickel-based composite material. The method comprises the following operation steps: 1, taking a nickel source, an iron source, an ammonium source, a surfactant and foam nickel, to be ultrasonically dispersed in a solvent A to prepare a precursor solution, putting the obtained precursor solution into a high-pressure kettle, reacting for 5-20 h in a high-pressure environment, cooling to room temperature after the reaction is finished, taking out, washing, and drying to obtain a nitrogen-doped FeNi-LDHs/NFnanometer array composite material; 2, putting the FeNi-LDHs/NF nanometer array composite material obtained in the step 1 into a synthesis solution of MOF, loading the MOF particles on the surface ofthe FeNi-LDHs/NF nanometer array composite material through a template oriented growth reaction, washing with water multiple times, and drying to obtain a FeNi-LDHs/MOF/NF nanometer array composite material; and 3, carrying out phosphorus doping, sulfur doping or oxidation reaction on the FeNi-LDHs/MOF/NF nanometer array composite material obtained in the step 2 to obtain the foam nickel-loaded iron-nickel-based composite material. According to the invention, the preparation method is simple to operate, the raw materials are easy to obtain, and the reaction conditions are easy to achieve.